Sampling on Ethernet CompactRIO Chassis

[electronbas]

Hi,

I'm using NI 9147 Chassis RIO with NI 9215 Analog Module.

Device configured for RT Scan mode and in scan engine properties scan period set for 1 ms.

My question is,

1. where to configure sampling rate setting for NI9215.  

2. Scan engine properties, scan period set for 1 ms. Does it mean maximum sampling rate 1000s/S.

3. Can i get from NI9215 100 kS/s/ch, 16-Bit, Simultaneous with this setup.

I'm totally confused, someone please help me on this.  

[GerdW]

Hi electronbas,

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@electronbas wrote:

My question is,

2. Scan engine properties, scan period set for 1 ms. Does it mean maximum sampling rate 1000s/S.

3. Can i get from NI9215 100 kS/s/ch, 16-Bit, Simultaneous with this setup.

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2. Yes, you will get (at most) 1kS/s with a scan period of 1ms.

3. No, you will not be able to read 100kS/s from your module when the ScanEngine only reads new (single!) samples each 1ms…

[electronbas]

Hello GerdW,

Thanks for your quick response.

Now i understood from your answer that Ethernet Compact RIO Chassis can sample 1 kS/s irrespective of IO module specification.

 Is your answer applicable for both RT scan mode and as well as FPGA programming on Ethernet Compact RIO Chassis?

Would you recommend cDAQ for NI9215 for achieving full sampling rate?

Thanks

[crossrulz]

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@electronbas wrote:

Would you recommend cDAQ for NI9215 for achieving full sampling rate?

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A single slot cDAQ would be the simplest route.  DAQmx does all of the work for you.  If you want Ethernet, then the cDAQ-9181 should do the job for you.

[GerdW · Accepted solution]

Hi electronbas,

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@electronbas wrote:

Now i understood from your answer that Ethernet Compact RIO Chassis can sample 1 kS/s irrespective of IO module specification.

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You understood wrong!

Even when you set the ScanEngine to read samples at 1kS/s it cannot read faster than the IO modules allow! There are several modules with samplerates of less than 100S/s…

To rephrase the sentence: you can read new samples with a samplerate of minimum(ScanEngine samplerate, module samplerate)!

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@electronbas wrote:

Is your answer applicable for both RT scan mode and as well as FPGA programming on Ethernet Compact RIO Chassis?

---

You explicitely asked for ScanEngine usage, so my answer only applies to ScanEngine mode!

Using FPGA you can utilize the full samplerate of your IO modules…

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@electronbas wrote:

Would you recommend cDAQ for NI9215 for achieving full sampling rate?

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As said before (by @crossrulz): using a single slot (USB?) cDAQ would allow for most simple DAQmx implementation of your NI9215 readings…

[electronbas]

Hi 

@Crossrulz thanks for your recommendation.

@GerdW thanks for your explanation and made me to understood.

NI9147 Ethernet Compact RIO Chassis, can be used for higher sampling >1kS.

If yes, how can i proceed?

[GerdW]

Hi electronbas,

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@electronbas wrote:

NI9147 Ethernet Compact RIO Chassis, can be used for higher sampling >1kS.

If yes, how can i proceed?

---

Use the FPGA examples for your modules to learn how to implement support for high samplerates (as high as supported by your modules).

Then implement FPGA code for your cRIO chassis.

(The ScanEngine is quite limited in its features/abilities.)

Use the (cRIO) example projects to learn how to transfer your "high speed" data to your computer. I recommend NetworkStreams…

[electronbas]

Hi GerdW,

Thanks for your time and support.

[ZYOng · Accepted solution]

NI-9147 has no controller and hence cannot use network stream.

You use DMA FIFO to stream data from FPGA to the host. You can find some examples at Help >> Find Examples... >> Hardware Input and Output >> compactRIO >> Fundamentals >> Data Transfer and Storage >> FPGA to Host >> Streaming Data (DMA) or Interleaving Channel Data (DMA)